The present invention relates to a device used to protect a catheter from contamination during and after the time the catheter is inserted into a venous lumen or other body cavity.
The invention is particularly useful for the protection of flow directed catheters used in the measurement of central venous pressure and pulmonary wedge pressure during and after cardio-pulmonary bypass surgical procedures. In these procedures, the patient is monitored using a pulmonary artery balloon tipped catheter having at least two lumens. The catheter is placed percutaneously before induction of anesthesia. In certain instances, it has been observed that the balloon of the catheter will fail to wedge after cardio-pulmonary bypass and the catheter has to be repositioned. Manipulation of the catheter to reposition it is recognized to the hazardous, because, over a period of time, exposed segments of the catheter may become contaminated, and introduction of the exposed portion may cause infection.
As is well known, a catheter is inserted through a vein, such as the right internal jugular vein or the subclavian vein, of the patient by inserting a hollow needle through which a stainless steel guide wire is then introduced into the lumen of the vein. A dilator and introducer system is then placed over the guide wire and into the vessel (i.e., Seldinger Technique). The dilator and guide wire are then removed, and the flow directed catheter is inserted and positioned through the introducer device. The normal practice also involves the use of a plastic protective sleeve which is tied or otherwise secured at one end to the introducer prior to introducing the catheter.
After the catheter has been completely advanced to the wedge position, the opposite end of the protective sleeve is fully extended over the catheter to a position remote from the introducer. This end is then fastened in place by a sterile fastening, so a length of catheter between the introducer and the opposite end of the protective sleeve is protected from contamination. The protected portion, which may be as long as 40 inches (100 cm.), can be advanced easily into the vein if the catheter again has to be moved to the wedge position due to dislodgement or migration.
Heretofore, there have been efforts made to incorporate a protective sleeve extending between a front hub and a rear hub, with a disconnectible guide tube means within the flexible protective sleeve. The guide tube facilitates feeding a catheter through the assembly comprising the plastic protective sleeve which extends between the pair of hubs, particularly when used with an adapter with a side port and a catheter introducer. Such efforts are shown in U.S. Pat. No. 4,327,723 entitled CATHETER SHIELD and in U.S. Pat. No. 4,327,735 entitled CATHETER ASSEMBLY, which patents are incorporated herein by reference to show both the state of the art and the manner in which a protective catheter shield assembly is used.
The devices described in the aforementioned patents failed to provide means for firmly connecting the catheter shield assembly to a catheter, in order to prevent movement of the catheter shield assembly along the catheter. In particular, one of the devices used rubber hubs with a hole bored through them, and the other device used a rubber band to hold the protective sleeve in place on the catheter. In both of these devices, the protective sleeve was found to slip on the catheter. In addition, the devices heretofore known used an internal feed tube through which a catheter was advanced. Disadvantages of the internal feed tube are that its internal diameter limits the external diameter of a catheter which can be passed therethrough, and that it fails to protect the flexible protective sleeve, which is left exposed. Accordingly, an improved apparatus for catheter placement and protection would be desirable.